Caenorhabditis elegans
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA356376 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR5079710.fastq.gz | Fastqsanger.gz | |||
| SRR5079701.fastq.gz | Fastqsanger.gz | |||
| SRR5079711.fastq.gz | Fastqsanger.gz | |||
| SRR5079702.fastq.gz | Fastqsanger.gz | |||
| SRR5079712.fastq.gz | Fastqsanger.gz |
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Project description:Eukaryotic cells express a wide variety of endogenous small regulatory RNAs that function in the nucleus. We previously found that erroneous rRNAs induce the generation of antisense ribosomal siRNAs (risiRNAs) which silence the expression of rRNAs via the nuclear RNAi defective (Nrde) pathway. To further understand the biological roles and mechanisms of this class of small regulatory RNAs, we conducted forward genetic screening to identify factors involved in risiRNA generation in Caenorhabditis elegans. We found that risiRNAs accumulated in the RNA exosome mutants. risiRNAs directed a NRDE-dependent silencing of pre-rRNAs in the nucleolus. In the presence of risiRNAs, NRDE-2 accumulated in the nucleolus and colocalized with RNA polymerase I. risiRNAs inhibited the transcription elongation of RNA polymerase I by decreasing RNAP I occupancy downstream of the RNAi-targeted site. Meanwhile, exosomes mislocalized from the nucleolus to nucleoplasm in suppressor of siRNA (susi) mutants, in which erroneous rRNAs accumulated. These results established a novel model of rRNA surveillance by combining ribonuclease-mediated RNA degradation with small RNA-directed nucleolar RNAi system.
2021-01-20 | GSE165078 | GEO
Project description:We analyzed the C. elegans small RNA response to high copy transgene sequences expressed in the soma in a wild type and an eri-6/7 mutant background. We also analyzed small RNA defects in the arl-8(tm2472) mutant. Transgene siRNAs are 22 nt long, mostly antisense, and correspond to the promoter, coding regions, the 3'UTR and plamsid sequences present on the transgene. Transgene siRNAs are decreased in the eri-6/7 mutant. In the arl-8 mutant, 26G siRNAs in the ALG-3/4 dependent endogenous RNAi pathway are decreased.
2013-12-15 | GSE52785 | GEO
Project description:Antisense ribosomal siRNAs (risiRNAs) downregulate pre-rRNAs through the nuclear RNAi pathway in Caenorhabditis elegans. However, the biogenesis and regulation of risiRNAs remain obscure. Previously, we showed that 26S rRNAs are uridylated at the 3'-ends by an unknown terminal polyuridylation polymerase before the rRNAs are degraded by a 3' to 5' exoribonuclease SUSI-1(ceDIS3L2). There are three polyuridylation polymerases, CDE-1, PUP-2, and PUP-3, in C. elegans. Here, we found that CDE-1 is specifically involved in suppressing risiRNA production. CDE-1 localizes to perinuclear granules in the germline and uridylates both Argonaute-associated 22G-RNAs and 26S rRNAs at the 3'-ends. Immunoprecipitation followed by mass spectrometry (IP-MS) revealed that CDE-1 interacts with SUSI-1(ceDIS3L2). Consistent with those results, both CDE-1 and SUSI-1(ceDIS3L2) are required for the inheritance of RNAi. Therefore, this work identified a rRNA surveillance machinery of rRNAs that couples terminal polyuridylation and degradation.
2020-08-14 | GSE139530 | GEO
Project description:Unrestricted movement of mobile genetic elements could cause pre-mature lethality in Drosophila melanogaster. Specifically, retro transposons can disrupt genomic integrity through insertions, deletions and chromosomal rearrangements. Therefore, eukaryotes have developed defense mechanisms to silence these elements. In Drosophila, endogenous small interfering (endo-siRNAs) repress retro transposon mobility in somatic cells. The generation of endo-siRNAs requires Dicer-2 processing of double-stranded RNA precursors, yet the origins of this precursor are unknown. Here we show that retro transposons in Dmel-2 cells produce sense and antisense transcripts and identify bonafide transcription start sites for these RNAs. We determine that retro transposon antisense transcripts are less polyadenylated than sense transcripts. RNA-seq and small RNA-seq upon Dicer-2 depletion showed global decrease in endo-siRNAs mapping to retro transposons and increased expression of both S and AS retro transposon transcripts. These data support a model in which double-stranded RNA precursors are derived from convergent transcription and retained in the nucleus. Dicer-2 processes these precursors into endo-siRNAs that silence both sense and antisense retro transposon transcripts. Reduction of sense retro transposon transcripts potentially lowers element specific protein levels required for movement. This mechanism preserves genomic integrity and is especially important for Drosophila fitness because mobile genetic elements are highly active.
2016-01-26 | GSE67725 | GEO
Project description:We analyzed the C. elegans small RNA response to high copy transgene sequences expressed in the soma in a wild type and an eri-6/7 mutant background. We also analyzed small RNA defects in the arl-8(tm2472) mutant. Transgene siRNAs are 22 nt long, mostly antisense, and correspond to the promoter, coding regions, the 3'UTR and plamsid sequences present on the transgene. Transgene siRNAs are decreased in the eri-6/7 mutant. In the arl-8 mutant, 26G siRNAs in the ALG-3/4 dependent endogenous RNAi pathway are decreased. Sequencing small RNAs from C. elegans transgenic strains and mutants.
2013-12-15 | E-GEOD-52785 | biostudies-arrayexpress
Project description:Background: Modification of RNAs, particularly at the terminals, is critical for various essential cell processes; for example, uridylation is implicated in tumorigenesis, proliferation, stem cell maintenance, and immune defense against viruses and retrotransposons. Ribosomal RNAs can be regulated by antisense ribosomal siRNAs (risiRNAs), which downregulate pre-rRNAs through the nuclear RNAi pathway in Caenorhabditis elegans. However, the biogenesis and regulation of risiRNAs remain obscure. Previously, we showed that 26S rRNAs are uridylated at the 3'-ends by an unknown terminal polyuridylation polymerase before the rRNAs are degraded by a 3’ to 5’ exoribonuclease SUSI-1(ceDIS3L2).Results: Here, we found that CDE-1, one of the three C.elegans polyuridylation polymerases (PUPs), is specifically involved in suppressing risiRNA production. CDE-1 localizes to perinuclear granules in the germline and uridylates Argonaute-associated 22G-RNAs, 26S and 5.8S rRNAs at the 3’-ends. Immunoprecipitation followed by mass spectrometry (IP-MS) revealed that CDE-1 interacts with SUSI-1(ceDIS3L2). Consistent with these results, both CDE-1 and SUSI-1(ceDIS3L2) are required for the inheritance of RNAi.Conclusions: This work identified a rRNA surveillance machinery of rRNAs that couples terminal polyuridylation and degradation.
2020-08-11 | GSE156000 | GEO
Project description:Small interfering RNAs (siRNAs) direct RNA interference (RNAi) in eukaryotes. In flies, somatic cells produce siRNAs from exogenous double-stranded RNA as a defense against viral infection. Here, we identify 21-nt long, endogenous siRNAs (endo-siRNAs) corresponding to transposons and heterochromatic sequences in the somatic cells of Drosophila melanogaster. We also detected endo-siRNAs complementary to mRNAs: these siRNAs disproportionately mapped to the complementary regions of overlapping mRNAs predicted to form dsRNA in vivo. Normal accumulation of somatic endo-siRNAs requires the siRNA-generating ribonuclease, Dicer-2, and the RNAi effector protein, Ago2. We propose that endo-siRNAs generated by the fly RNAi pathway silence selfish genetic elements in the soma much as piRNAs do in the germ line. Keywords: Small RNA detection and quantification.
2008-04-11 | GSE11019 | GEO
Project description:Biological function of antisense RNAs that are synthesized by RNA-dependent RNA polymerases under rehydration
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Project description:Biological function of antisense RNAs that are synthesized by RNA-dependent RNA polymerases under abiotic stress
| PRJNA293711 | ENA
Project description:In flies, repeat-associated small interfering RNAs (rasiRNAs) ensure genomic stability by silencing endogenous selfish genetic elements such as retrotransposons and repetitive sequences. Here, we show that while small interfering RNAs (siRNAs) derive from both the sense and antisense strands of their double-stranded RNA precursors, rasiRNAs arise mainly from the antisense strand. rasiRNA production appear not to require Dicer-1, which makes microRNAs, or Dicer-2, which makes siRNAs, and rasiRNAs lack the 2´,3´ hydroxy termini characteristic of animal siRNA and miRNA. Unlike siRNAs and miRNAs, rasiRNAs function through the Piwi, rather than the Ago, Argonaute protein subfamily. Thus, rasiRNAs define a third RNA silencing pathway distinct from both the miRNA and RNAi pathways. Keywords: gene silencing; post-transcriptional gene regulation; short RNAs; RNAi; rasiRNAs; rasiRNA; microRNAs; microRNA; siRNAs; siRNA
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